Troubleshooting Your Network Connection

NEW VIDEO!
Link to the Consulting on Demand web site to watch a short video that takes you step-by-step through the connection process. You can view the video on either a Windows- or Macintosh-based computer.

1. My laptop has both an Ethernet adapter and a wireless adapter, but I cannot connect to the Internet.

2. How do I disable/enable my wireless adapter for a Windows Vista or Windows XP computer?

3. How do I release/renew the IP address for my computer?

4. I can use my web browser to connect to the University's home page, the Library, and other on-campus sites, but I can't get to web sites outside the University of Delaware.

5. My computer worked at home using a dial-in connection. Now that I'm using an on-campus Ethernet connection, whenever I start Internet Explorer my computer tries to dial-in using the modem.

6. I've registered both my computer's Ethernet adapter and its wireless adapter, but I can't connect to the Internet due to a duplicate IP address error.

7. I received an e-mail message saying my computer is running a DHCP process that is interfering with the network. What do I do?

8. I can't connect to the Internet. I see an error message about an IP address 169.254.0.0.

9. I see too many pop-up ads when I open my web browser. And, my computer is so slow!

10. When I start my computer, I see the error message, "Error 38. The computer name you specified is already in use on the network.

11. When I boot up my computer, I see a Windows pop-up balloon with the message: "There is an IP address conflict with another system on the network."

12. My Ethernet adapter is installed correctly, and I am not receiving any error messages. However, I still cannot connect to the network.

13. I can ping, but I can't read e-mail or browse the web using Internet Explorer. I see the error message, "Page can not be displayed."

14. I have a Dell Inspiron 1705 computer. If I don't have my AC adapter plugged in, I cannot connect to the Internet. How can I fix this problem?

My laptop has both an Ethernet adapter and a wireless adapter, but I cannot connect to the Internet.

You need to make sure that both your Ethernet adapter and wireless adapter are registered for your computer. You must register each one separately, and you must use only ONE at a time.

To register your computer through your Ethernet adapter, do the following:

1. Disable the wireless adapter. Connect your computer's Ethernet cable to the Ethernet jack in your dorm room. Connect to UD's Network page and follow the instructions to log in. Select Register a computer for Internet Access.
2. Follow the on-screen instructions to register the computer.

To register your computer through your wireless adapter, do the following:

1. Unplug your Ethernet cable from the Ethernet jack in your dorm room. Enable the wireless adapter. Check to see if you have a strong wireless signal in your room. If you do not, go to the lounge area of your dorm. When you have a strong wireless signal, connect to UD's Network page and follow the instructions to log in. Select Register a computer for Internet Access.
2. Follow the on-screen instructions to register the computer.

IMPORTANT NOTE
If you are a student and have successfully registered both your wireless adapter and your Ethernet adapter, you must use them ONE at a time. If both adapters attempt to connect simultaneouly, you will be unable to connect due to a duplicate IP address error. Follow these directions.

NOTE
After you have enabled your wireless adapter, you must turn on your wireless device to connect to the Inernet. There are a number of ways to turn on/off your wireless device. On many laptop computers, there is a "shortcut" to toggle the wireless device on and off. You should check your computer's User's Guide to find this shortcut for your computer. However, in general, these shortcuts are usually one of the following:

• a key on or near the keyboard that you press (usually the key will have a graphic that represents a wireless network device)
• a function key combination (on a Dell or Gateway laptop, it is usually the FUNCTION-F2 key combination), or
• a slider switch.

For example, the following graphic shows a typical slider switch located on the side of a laptop computer; when the wireless connection is enabled, a green light is on.

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How do I disable/enable my wireless adapter for a Windows Vista or a Windows XP computer?

Windows Vista Computer
To disable your wireless adapter (which you must set under the computer's Network and Sharing Center):

1. Click Start.
2. Click Control Panel.
3. Double-click Network and Sharing Center.
4. In the left-hand column, click Manage network connections.
5. Right-click the Wireless Network Connection icon.
6. Click Disable.

To enable your wireless adapter (which you must set under the computer's Network and Sharing Center):

1. Click Start.
2. Click Control Panel.
3. Double-click Network and Sharing Center.
4. In the left-hand column, click Manage network connections.
5. Right-click the Wireless Network Connection icon.
6. Click Enable.

Windows XP Computer
To disable your wireless adapter (which you must set under the computer's Network Connections):

1. Click Start.
2. Click Control Panel.
3. Double-click Network Connections.
4. Right-click Wireless Network Connection.
5. Click Disable.

To enable your wireless adapter (which you must set under the computer's Network Connections):

1. Click Start.
2. Click Control Panel.
3. Double-click Network Connections.
4. Right-click Wireless Network Connection.
5. Click Enable.

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How do I release/renew the IP address for my computer?

The instructions on how to release/renew the IP address for your computer depends on the operating system that you use. Instructions for Windows Vista, Windows XP, and Mac OS X are outlined below.

1. Click Start. Your cursor will appear in the Start Search field.
2. In the Start Search field, type

cmd

and press the key combination SHIFT-CTRL-ENTER.

3. When you see the User Account Control dialog box, click Continue.
4. A window with a black background should appear.
5. In the window, type

ipconfig /release

6. Press ENTER.

NOTE
You must insert one blank space between ipconfig and /release

7. In the window, type

ipconfig /renew

8. Press ENTER.

NOTE
You must insert one blank space between ipconfig and /renew

The renew command takes longer to execute than the release command. When renewal is complete, the system should respond with an IP address of 10.x.x.x or 128.175.x.x (x is a number).

9. Link to the Network page to login and register your computer.

1. Click Start.
2. Click Run.
3. In the Open field, type

cmd

4. Click OK. You should see a window with a black background appear.
5. Type

ipconfig /release

6. Press ENTER.

NOTE
You must insert one blank space between ipconfig and /release

If the system returns the message, no such command or displays Help text, the command was probably typed incorrectly.
If the system returns the message IP configuration and no further information, make sure your Internet Protocol Properties (TCP/IP) are set as:

• Obtain an IP address automatically
• Obtain DNS server address automatically

The system should respond with an IP address of 0.0.0.0 (all zeros).

7. Type

ipconfig /renew

8. Press ENTER.

NOTE
You must insert one blank space between ipconfig and /renew

If the system returns the message, no such command or displays Help text, the command was probably typed incorrectly.
If the system returns the message IP configuration and no further information, make sure your Internet Protocol Properties (TCP/IP) are set as:

• Obtain an IP address automatically
• Obtain DNS server address automatically

The renew command takes longer to execute than the release command. When renewal is complete, the system should respond with an IP address of 10.x.x.x or 128.175.x.x (x is a number).

9. Link to the Network page to login and register your computer.

1. From the Apple Menu, click System Preferences.
2. Click Network.
3. From the Show pop-up menu, click Network Port Configurations.
4. Click in the checkbox in front of the Network configuration you want to release to remove the check mark (Built-in Ethernet or AirPort).
5. Click Apply Now.
6. Click in the checkbox in front of the Network configuration you just unchecked to turn the configuration back on.
7. Click Apply Now.
8. Link to the Network page to login and register your computer.

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I've registered both my computer's Ethernet adapter and its wireless adapter, but I can't connect to the Internet due to a duplicate IP address error.

If you are a student and have successfully registered both your wireless adapter and your Ethernet adapter, you must use them one at a time. If both adapters attempt to connect simultaneouly, you will be unable to connect due to a duplicate IP address error. Follow these directions.

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I received an e-mail message saying my computer is running a DHCP process that is interfering with the network. What do I do?

If your computer was set up on your home network and configured to allow Internet Connection Sharing, you must turn that feature off when connecting to UD's network. Click here for more information and step-by-step instructions on how to do this.

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I can use my web browser to connect to the University's home page, the Library, and other on-campus sites, but I can't get to web sites outside the University of Delaware.

1. Visit http://www.udel.edu/network using your own computer.
2. Use your UDelNet ID and password or UD ID and PIN to log in. ONLY use your Social Security Number (SSN) and PIN if you have not yet created a UDelNet ID and password.
3. Choose Register a computer for Internet Access.
4. Click on the box to register your computer. After you register your computer, you will need to wait at least 30 minutes for the changes to take effect.
5. Reboot your computer.

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I can't connect to the Internet. I see an error message about an IP address that begins with 169.254.0.0.

• Check the Ethernet cable—borrow an Ethernet cable that you know works and try to connect using it.
• Improper LAN Connection Proxy setting:
• Click Start | Control Panel | Internet Options.
• Click the Connections tab.
• Click LAN Settings at the bottom of the window.
• On the Local Area Network (LAN) settings window, UNCHECK all items currently checked.
• Reboot the computer.
• Check the Ethernet port.
• Call the Help Desk at 831-6000 to check if a port is disabled.

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I see too many pop-up ads when I open my web browser. And, my computer is so slow!

Spyware is most likely responsible for redirecting or hijacking your browser settings. Go to http://www.udel.edu/security. At the top of the page, click on the link for your operating system. Follow the instructions for how to "Remove and Protect against Spyware."

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When I start my computer, I see the error message: "Error 38. The computer name you specified is already in use on the network."

Windows XP Computers

1. Right click My Computer.
2. Choose Properties.
3. Select the Computer Name tab.
4. Click Change.
5. Change the Computer Name field to your UDelNet ID (i.e., your e-mail username--e.g., jsmith).
6. Click OK until you are back at your computer's desktop.
7. Reboot your computer.

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When I boot up my computer, I see a Windows pop-up balloon with the message: "There is an IP address conflict with another system on the network."

NOTE
For Windows XP computers, you will not see the IP address. You will need to find it using the following steps:

1. Click Start.
2. Click Control Panel.
3. Double-click Administrative Tools.
4. Double-click Event Viewer.
5. Click System Log in the right-hand side of the window.
6. Look for an entry under the Source column with the letters TCPIP.
7. Double-click the entry to bring up a detailed description of the problem, including the IP address of the conflicting network adapter, which you need to write down before you call the Help Center at 831-6000.
8. Call 831-6000 while you are experiencing this problem. Keep your computer turned on.
   • Select option 1 from the voice menu.
   • Press 0.
   • You will need to provide the Help Center staff with your name, residence hall, room number, phone number, AND the IP address and hardware address from the error message.
   • Leave your computer on--do not shut it off--until the problem is fixed. A staff member will contact you when the problem has been resolved.

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My Ethernet adapter is installed correctly, and I am not receiving any error messages. However, I still cannot connect to the network.

1. Check the cable and wall jack to be sure they are working.
• Check to make sure that your Ethernet cable is securely plugged into the Ethernet adapter or adapter and into an active jack in the wall. The plugs on a 10Base-T Ethernet cable look like larger versions of the plugs on a telephone cable.
• In many residence hall rooms, the Ethernet jacks have a red label and the phone jacks have a blue label.

  

  In some residence halls on North Campus, both jacks are grey; however, the Ethernet jacks are usually on the right-hand side.

  

  Most Ethernet jacks also have an icon of a computer. The phone jacks usually have an icon of a phone on them.

• Try moving your Ethernet cable from one Ethernet jack to another. The one to the left is usually the first jack activated.
• Does your roommate's computer connect to the network? If so, first try using his or her cable and your wall jack. If that fixes the problem, you have a bad Ethernet cable. If your cable works in your roommate's Ethernet jack, call 831-6000 and request that your wall jack be checked.
2. Check your Ethernet adapter and TCP/IP software.
   • With the computer running, look at the back of the Ethernet adapter for a green light. If the green light is not on, the adapter may be improperly configured or the wall jack you are trying to use may not be active.
   • If the green light on your Ethernet adapter is on, but you are still unable to connect, call 831-8825.

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My computer worked at home using a dial-in connection. Now that I'm using an on-campus Ethernet connection, whenever I start Internet Explorer, my computer tries to dial-in using the modem.

1. Click Start.
2. Double-click Control Panel.
3. Double-click Internet Options.
4. Click the Connections tab.
5. Click the appropriate radio button under the Dial-up settings window so that Dial whenever a network connection is not present is selected.
6. Click OK.

This is a particularly efficient setting for laptop computers: if your computer senses the modem is connected, it will dial in; if it senses that your Ethernet connection is active, it will use that connection.

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I can ping, but I can't read e-mail or browse the web using Internet Explorer. I see the error message, "Page cannot be displayed."

Return to Contents

How do I release/renew the IP address for my computer?

The instructions on how to release/renew the IP address for your computer depends on the operating system that you use. Instructions for Windows Vista, Windows XP, and Mac OS X are outlined below.

1. Click Start. Your cursor will appear in the Start Search field.
2. In the Start Search field, type

cmd

and press the key combination SHIFT-CTRL-ENTER.

3. When you see the User Account Control dialog box, click Continue.
4. A window with a black background should appear.
5. In the window, type

ipconfig /release

6. Press ENTER.

NOTE
You must insert one blank space between ipconfig and /release

7. In the window, type

ipconfig /renew

8. Press ENTER.

NOTE
You must insert one blank space between ipconfig and /renew

The renew command takes longer to execute than the release command. When renewal is complete, the system should respond with an IP address of 10.x.x.x or 128.175.x.x (x is a number).

9. Link to the Network page to login and register your computer.

1. Click Start.
2. Click Run.
3. In the Open field, type

cmd

4. Click OK. You should see a window with a black background appear.
5. Type

ipconfig /release

6. Press ENTER.

NOTE
You must insert one blank space between ipconfig and /release

If the system returns the message, no such command or displays Help text, the command was probably typed incorrectly.
If the system returns the message IP configuration and no further information, make sure your Internet Protocol Properties (TCP/IP) are set as:

• Obtain an IP address automatically
• Obtain DNS server address automatically

The system should respond with an IP address of 0.0.0.0 (all zeros).

7. Type

ipconfig /renew

8. Press ENTER.

NOTE
You must insert one blank space between ipconfig and /renew

If the system returns the message, no such command or displays Help text, the command was probably typed incorrectly.
If the system returns the message IP configuration and no further information, make sure your Internet Protocol Properties (TCP/IP) are set as:

• Obtain an IP address automatically
• Obtain DNS server address automatically

The renew command takes longer to execute than the release command. When renewal is complete, the system should respond with an IP address of 10.x.x.x or 128.175.x.x (x is a number).

9. Link to the Network page to login and register your computer.

1. From the Apple Menu, click System Preferences.
2. Click Network.
3. From the Show pop-up menu, click Network Port Configurations.
4. Click in the checkbox in front of the Network configuration you want to release to remove the check mark (Built-in Ethernet or AirPort).
5. Click Apply Now.
6. Click in the checkbox in front of the Network configuration you just unchecked to turn the configuration back on.
7. Click Apply Now.
8. Link to the Network page to login and register your computer.

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I have a Dell Inspiron 1705 computer. If I don't have my AC adapter plugged in, I cannot connect to the Internet. How can I fix this problem?

If you have this problem, one of the power management settings on your computer is set so that the computer shuts down to save power. You can change this setting by following these steps:

1. Click Start.
2. Right-click My Computer.
3. Click Properties.
4. Click the Hardware tab.
5. Click Device Manager.
6. Click the plus sign (+) in front of Network Adapters.
7. Double-click the name of your Ethernet adapter.
8. Click the Power Management tab.
9. Remove the check mark in front of the Allow the computer to turn off this device to save power option.
10. Restart your computer.

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Last updated August 10, 2007
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